1. Field of the Invention
This invention relates to accessories for assisting in bleeding the hydraulic fluid from the brake system of automobiles and trucks. By use of the present invention, it is possible for one person to bleed the brake system through the wheel cylinders of all four wheels simultaneously.
2. Description of the Prior Art
For many years, it has required two people in order to bleed the brake system of hydraulic fluid in order to eliminate any air in the system. Usually, one person sits in the car, behind the wheel, and operates the brake pedal upon command from the other person who is working under the car and operating the bleeder valve, that is furnished with each wheel cylinder, by moving it between a closed and an open position.
It has been a desired objective for many years to devise a brake system that requires but one person to bleed the hydraulic brakes. An early patent is the Gary et al U.S. Pat. No. 2,069,606 which describes a bleeder valve that is furnished with a one-way ball check valve, which check valve prevents air from being drawn in through the discharge end of the bleeder valve when the brake pedal is released. This patent also has a modification that includes the addition of an outlet valve associated with a pipeline leading from the one-way bleeder valve, where this outlet valve serves to release any accumulated air that is present in the hydraulic fluid, thereby eliminating any possibility of the accumulated air returning into the hydraulic brake system.
The Legerski U.S. Pat. No. 2,611,387 describes a valved tool for bleeding brake cylinders. This patent teaches the use of a flexible hose that is connected to the standard bleeder valve, and the free end of the hose is supplied with a small, portable tool having a hollow body formed by a pair of mating cylindrical parts having two ball check valves that are held closed by a common compression spring with a single discharge opening located between the two check valves. The reason for the two ball check valves is that the tool may be used in one direction for use with standard automobiles, and then it could be used in a reverse position for use with larger vehicles, such as trucks, airplanes and the like.
The Wilson U.S. Pat. No. 2,771,093 describes a bleeder valve for hydraulic brake systems, where the bleeder valve has a one-way check valve for preventing the entrance of air into the system during the time the bleeder valve is open and while fluid and air is passing therethrough. This bleeder valve having a one-way check valve is also a one person brake-bleeder system. A drain hose is shown connected to this bleeder valve for discharging into a suitable receptacle.
The Pagano U.S. Pat. No. 3,050,080 describes a bleeder valve having a pair of ball check valves that are held closed by a common intermediate compression spring. The purpose of the outermost check valve is to prevent foreign matter from entering into this one-way check valve.
The Berg U.S. Pat. No. 4,149,560 describes a one-way check valve that may be releasibly attached to the bleeder valve of a wheel brake cylinder. This one-way bleeder valve has a quick disconnect in the form of a rubber casing or jacket that fits over the one-way check valve and is capable of snapping over the external fitting of the bleeder valve.